You could cut the atmosphere with a knife at the end of the Shanghai derby on Saturday evening – and some Shanghai Shenhua fans were doing just that, running their fingers across their throats as they looked to the stands above them for SIPG supporters who had braved the home end.

It was all very different 24 hours before speaking to a Chase, a Shanghainese football fan in his 20s, flying back from Hong Kong to Shanghai. He wasn’t planning on going to the game but had been to the last league meeting between the sides at Shanghai Stadium and paid handsomely for the pleasure – two tickets for 1,000 yuan. He was rewarded for that outlay with seeing a 5-0 win for SIPG, not ideal for someone, like most Shanghai’s football loving residents, who grew up supporting Shenhua.

Payback for that hammering was swift for Shenhua, winning the FA Cup on the same ground and making sure the arrivistes remained trophyless.

Incidents like that may stoke the fires but as Chase explained the divide between red and blue runs deeper, with Shanghai International Port Group’s 2012 takeover and subsequent spending losing what goodwill had existed.

At that time Shenhua were still in the Zhu Jun era, the egotistical chairman whose ownership of the club saw Didier Drogba and Nicolas Anelka arrive and leave supposedly unpaid. At the time Shenhua shirts were adorned with Zhu’s Firefall game – a fitting portmanteau of the free fall he put the club in and the fire sale of players, particularly Shanghainese, he oversaw.

Chase explained that he fell out of love a little with Shenhua under Zhu but mostly because of the playing style, which became too “rude”, no longer the traditional “gentle” Shanghai brand of football the club had traditionally played.

He could hardly go to support SIPG, though. Shenhua dominates, as the club crest my Metallica-blasting cab driver’s phone screen saver showed.

During the opening minutes of the game I had been asked if I was an SIPG fan by a foreigner who has followed Shenhua for years. I had taken the question for macho posturing but as rumours swirled around the ground and eyes followed them from the pitch to the stands, searching for where the unwelcome visitors were it became clear that a handful of SIPG fans had held their nerve enough to sneak into the Shenhua stands but could not hold their tongues.

This being China and 2018, videos were soon on social media. There were several fans sent packing from the stands, one of which showed a foreigner who had apparently changed from a blue shirt to a red one during the game and been advised in the strongest terms that a line had been crossed.

They should all have known better and were lucky to get away with it without injury.

Tempers run highest at the derby and there was a large police presence because of that and the number of officers was only matched by that of ticket touts around the stadium, including some at the bottom of the escalators in Hongkou Plaza, the shopping centre alongside the stadium.

The derby was officially sold out weeks ago but clearly not all the tickets had found their way to matchgoing fans and the good people of Shanghai were willing to make a quick buck in making sure they got in the right hands – in hindsight, maybe not all of them.

Inside the ground the scenes were a stark contrast to the Guangzhou sides meeting on opening day.

The crackle of electricity in the air underpinned with the enmity that makes sports so exciting. Unlike some of the others in the Chinese Super League, where teams have been moved around the country as corporate playthings, no one could argue that this game is not a real derby.

On the pitch, it was high on passion and low on quality. Early yellow cards setting the tone.

World class atmosphere at Hongkou Stadium for the Shanghai derby. Shenhua fans kept it rocking for 90 minutes, clapped the team off despite the loss and then went back to the important business of abusing SIPG fans. A proper destination derby. pic.twitter.com/o4StmfU0f8